1. FIELD OF THE INVENTION
The present invention is generally directed to the improvement of processors. More specifically, this invention pertains to a general-purpose processor that is required to perform a variety of operations, wherein a data bitwidth is divided into adequate lengths depending upon the type of processing. By virtue of the ability to make a change in the data bitwidth, the prevention of redundancy can be accomplished, and an extra bitwidth is used in other operations.
2. DESCRIPTION OF THE PRIOR ART
The processing capability of processors has been dramatically improved in recent years. With the improvement, there have been strong demands for high-performance processors capable of performing various types of tasks such as the controlling of various devices and the processing of video/audio signals.
Commonly-used high-performance processors of the above-described type have a great bitwidth, for greater bitwidth performs greater amount of data.
In the multimedia age, the type of data, intended for execution by a single processor, ranges wide from data for use in the processing of audio signals requiring a great bitwidth, to data for use in the processing of video signals requiring a less bitwidth.
Accordingly, the choice of which type of processor to use is based on data that requires the greatest bitwidth. This produces the problem that even data requiring a less bitwidth is processed at a redundant bitwidth (i.e., the greatest bitwidth). In general, 32-bit processors are used in the processing of audio signals when good sound quality is important. On the other hand, 16-bit processors can manage to operate successfully in many cases when used for processing video signals. Further, an 8-bit processor may be sufficient when employed to perform simple control operations. In cases where all of audio signal processing, video signal processing, and simple control operation are carried out in a single processor, both the video signal processing and the simple control operation are indiscriminately performed using a redundant bitwidth, although they can be performed at a less bitwidth.
To cope with the above-described inconvenience, a technique is proposed in which data are pallelized and a plurality of narrow bitwidth data are subjected to simultaneous processing by a wide bitwidth processor, with a view to providing improved processing performance. However, in cases where serial processing, such as condition branch processing, is required to execute, it is impossible to subject a plurality of data to parallelization, resulting in providing no improvements in processor processing performance. On the contrary, use of an expensive processor results in increasing the equipment's entire cost.
A solution for lowering costs may be taken in which an equal number of processors to the number of operations are placed instead of using a single, costly processor, and the bitwidths of the processors are set to suite for their respective operations. This requires both high-performance, inexpensive processors having a wide bitwidth for signal processing and low-price processors having a narrow bitwidth for serial processing. As a result, the number of components increases thereby resulting in an increase in the entire size of equipment.